[Linux, Gnome on Wayland 49.0-49.2, 50alpha] Submenus don't open in the View menu on the 2D toolbar when the system display scale is 125%

[comminux]

Tested versions

• Reproducible in: 4.5.stable, 4.5.1-rc2, 4.6-dev1

System information

Godot v4.5.1.rc2 - Arch Linux #1 SMP PREEMPT_DYNAMIC Mon, 06 Oct 2025 18:48:29 +0000 on Wayland - Wayland display driver, Multi-window, 1 monitor - Vulkan (Forward+) - integrated Intel(R) UHD Graphics (TGL GT2) - 11th Gen Intel(R) Core(TM) i3-1115G4 @ 3.00GHz (4 threads) - 15.39 GiB memory

Issue description

Submenus don't open in the View menu on a 2D screen.

Interestingly, these submenus open normally on the 3D screen.

Steps to reproduce

• Go to the 2D view
• Open the View menu on the panel
• Select one of the submenus

Minimal reproduction project (MRP)

None

[comminux]

This issue remains relevant for Godot v4.6.beta2.

https://youtube.com/shorts/KpcgtAcs8Bk?feature=share

[comminux]

@deralmas Excuse me, could you look at this problem?

[deralmas]

Hi, thank you for reporting!

I can't seem to replicate it as of commit 5cb1ec5 on sway 1.11.

Could you please send me a debug log?

WAYLAND_DEBUG=1 path/to/godot --verbose 2>&1 | tee debug.log

Please note that this is a Wayland protocol dump and will include any input sent to the editor.

[comminux]

I have prepared the required log and screen recording.

debug.log

https://youtu.be/aqrQrwoG5jg

gnome-shell 49.2
godot v4.6.beta.custom_build [6f15a05]

[deralmas]

Hi, I can replicate this in a VM with Fedora 43, gnome 49.2. The weird thing is that this seems to happen only at 1.25 scale. Grepping for xdg_popup in WAYLAND_DEBUG, I can see an infinite loop where the popup gets immediately dismissed by the compositor (xdg_popup.popup_done) after it gets configured. Note that it does not happen on sway even with various fractional scales.

I'm seriously not sure what (if anything) we are doing wrong. As a matter of fact, xdg_popup::popup_done is an event that we can't trigger ourselves. The spec talks about dismissing a popup by destroying it, but I'm pretty sure that deleting an xdg_popup does not trigger said event. It's more like a server-initiated destructor.

Maybe it's a compositor bug? Can't find much in the bug tracker and I'm not even sure where to start. It's so oddly specific and precise. Moving and resizing the window around doesn't change much either.

I tried running the latest mutter commit in the VM from a toolbx container like per the docs, but I could not figure out how to enable fractional scale there. Maybe you could give mutter-git a try since you have the AUR at hand.

[comminux]

I enabled the gnome-unstable repository and replicated the issue on gnome-shell 50alpha-1.
I'm currently using KDE, where even at 125% zoom, all menus open correctly.

Nothing to add yet, but if I have anything useful, I'll share it in this issue.

I might check this patch a little later: https://gitlab.gnome.org/GNOME/mutter/-/issues/4465#note_2621375
Don't know how relevant it will be.

[comminux]

Patch for mutter didn't change the behavior in any way.

However, I'd like to point out that the issue with the View menu items only occurs in the 2D toolbar, not in 3D. It seems to me there's some difference between the two menus. Could you please tell me which engine files define this behavior?

Scaling settings can be accessed by right-clicking on the desktop in the Display Settings submenu.

Update. You are right, the scaling settings in Gnome also have an effect.

Gnome scale 100%, Godot 125%:

Gnome scale 125%, Godot 125%:

I was also able to reproduce the problem with 125% scaling in Gnome and 100% scaling in Godot.

Open issue in the Mutter repository: https://gitlab.gnome.org/GNOME/mutter/-/issues/4562

[deralmas]

However, I'd like to point out that the issue with the View menu items only occurs in the 2D toolbar, not in 3D. It seems to me there's some difference between the two menus.

I'm not aware of any substantial difference, outside of the relative position in the window. The protocol dump didn't report anything out of the ordinary either. I just now noticed a warning but it feels like a consequence of the bug, not the way around:

WARNING: _activate_submenu should not be called on an open submenu - index: 0.
     at: _activate_submenu (scene/gui/popup_menu.cpp:356)

Could you please tell me which engine files define this behavior?

Here is the initialization logic for the "Grid" submenu:

godot/editor/scene/canvas_item_editor_plugin.cpp

Lines 5912 to 5920 in 5f9a510

	grid_menu = memnew(PopupMenu);
	grid_menu->connect("about_to_popup", callable_mp(this, &CanvasItemEditor::_prepare_grid_menu));
	grid_menu->connect(SceneStringName(id_pressed), callable_mp(this, &CanvasItemEditor::_on_grid_menu_id_pressed));
	grid_menu->add_radio_check_item(TTRC("Show"), GRID_VISIBILITY_SHOW);
	grid_menu->add_radio_check_item(TTRC("Show When Snapping"), GRID_VISIBILITY_SHOW_WHEN_SNAPPING);
	grid_menu->add_radio_check_item(TTRC("Hide"), GRID_VISIBILITY_HIDE);
	grid_menu->add_separator();
	grid_menu->add_shortcut(ED_SHORTCUT("canvas_item_editor/toggle_grid", TTRC("Toggle Grid"), KeyModifierMask::CMD_OR_CTRL | Key::APOSTROPHE));
	p->add_submenu_node_item(TTRC("Grid"), grid_menu);

And here is the initialization logic for the "Gizmos" submenu (before getting procedurally filled with other stuff):

godot/editor/scene/3d/node_3d_editor_plugin.cpp

Lines 10008 to 10012 in 5f9a510

	gizmos_menu = memnew(PopupMenu);
	gizmos_menu->set_auto_translate_mode(AUTO_TRANSLATE_MODE_DISABLED);
	gizmos_menu->set_hide_on_checkable_item_selection(false);
	p->add_submenu_node_item(TTRC("Gizmos"), gizmos_menu);
	gizmos_menu->connect(SceneStringName(id_pressed), callable_mp(this, &Node3DEditor::_menu_gizmo_toggled));

It's all pretty generic stuff through the PopupMenu API. The fact that this works on other compositors is weird. Maybe it's a compositor bug but I'm not really sure how.

Scaling settings can be accessed by right-clicking on the desktop in the Display Settings submenu.

I tried but unfortunately the dummy display used for the mutter devkit option seems to enable only integer scale by default. I'm not sure how to make it accept fractional scales. When run directly in the VM it accepts fractional scaling fine.